Potamogeton ×jacobsii (Potamogetonaceae) from New South Wales, Australia – the first Potamogeton hybrid from the Southern Hemisphere

Abstract

Although more than 80 hybrids are documented for Potamogeton in the Northern Hemisphere, the hybrid diversity in the Southern Hemisphere is largely unknown. A taxonomically uncertain Potamogeton plant discovered in New South Wales, Australia, was subjected to detailed morphological investigation and molecular analyses to discover its exact identity. Both approaches resulted in the identification of the Potamogeton specimen as P. crispus × P. ochreatus, which is a previously unrecorded hybrid and is here described as Potamogeton × jacobsii nothosp. nova. Although P. crispus is known to hybridise with many other species, P. ×jacobsii is the first known hybrid involving P. ochreatus.

Taxonomic treatment and phylogenetic analysis of the family Potamogetonaceae in Turkey

“…Fruits are often not produced in running water, which can sometimes be incorrectly interpreted as evidence of sterility (Kaplan, 2008). Although hybrids in Potamogetonaceae were first recognized already in the late 19th century (see Kaplan & al., 2009 for a brief review), molecular evidence became available only during the past decades by using isozyme electrophoresis (e.g., Hollingsworth & al., 1995; Fant & al., 2001; Iida & Kadono, 2002; Kaplan & al., 2002; Kaplan & Wolff, 2004; Kaplan, 2007; Bobrov & Sinjushin, 2008) and DNA‐based techniques (e.g., King & al., 2001; Fant & al., 2003; Kaplan & Fehrer, 2004, 2009, 2011, 2013; Ito & al., 2007, 2014; Du & al., 2009, 2010; Les & al., 2009; Zalewska‐Gałosz & al., 2009, 2010, 2018; Kaplan & al., 2011, 2018; Aykurt & al., 2017; Iida & al., 2018). While these studies focused on hybrids, a few of them performed also phylogenetic analyses (e.g., Les & al., 2009; Kaplan & Fehrer, 2011; Ito & al., 2014; Kaplan & al., 2018; Zalewska‐Gałosz & al., 2018), but these include only taxa relevant for the identification of hybrids.…”

The endangered Florida pondweed (Potamogeton floridanus) is a hybrid: Why we need to understand biodiversity thoroughly

“…Previous studies showed that due to founder effect and prevailing clonal growth, genetic variation is low or absent within populations of Potamogeton species [ 10 , 14 , 65 – 66 ], and entirely absent in sterile colonies of Potamogeton hybrids [ 67 – 71 ]. Also intraspecific genetic variation in Potamogeton is generally very low or absent [ 34 , 45 , 65 ], even at continental scales ([ 40 , 42 ], and Fehrer & Kaplan, unpublished data). We therefore chose from our molecular database of Potamogetonaceae based on broad, worldwide sampling (including 3–32 populations of each above-mentioned species depending on rarity, 15 on average) single representative sequences of North American origin (except for the Asian / Australian taxa) per species and molecular marker except for P .…”

“…Recent studies on Potamogeton show that even in relatively well explored areas such as Europe or North America, the origin of the observed variation is poorly understood, and a great deal of the diversity is neglected and remains undetected [ 11 – 12 , 39 – 40 ]. Molecular analyses have recently contributed to elucidate the systematic position of taxonomically uncertain local forms [ 15 , 41 ], the discovery or exact identification of several entirely new hybrid combinations [ 11 , 40 , 42 – 46 ] and even confirmed the existence of a triple hybrid in Potamogeton [ 47 ].…”

Multivariate morphometric analysis of the Potamogeton compressus group (Potamogetonaceae)

“…Recent studies on Potamogeton taxonomy have concentrated mainly on the occurrence and diversity of hybrids (e.g. Preston, Bailey & Hollingsworth, 1998; Kaplan, 2001a, 2005a, 2007; Kaplan et al ., 2002, 2009; Fant, Kamau & Preston, 2003; Kaplan & Fehrer, 2004, 2006, 2009, 2011; Kaplan & Wolff, 2004; Kaplan & Zalewska‐Gałosz, 2004; Zalewska‐Gałosz, Ronikier & Kaplan, 2009, 2010; Kaplan, Fehrer & Hellquist, 2011; Kaplan & Uotila, 2011). Only a few studies have recently dealt with the morphological delimitation of species (e.g.…”

“…The main sources of taxonomic complexity include the reduced morphology, which limits the number of taxonomic characters that can be used to separate species (Preston & Croft, 1997;Kaplan & Štěpánek, 2003; Recent studies on Potamogeton taxonomy have concentrated mainly on the occurrence and diversity of hybrids (e.g. Preston, Bailey & Hollingsworth, 1998;Kaplan, 2001aKaplan, , 2005aKaplan, , 2007Kaplan et al, 2002Fant, Kamau & Preston, 2003;Kaplan & Fehrer, 2004Kaplan & Wolff, 2004;Kaplan & Zalewska-Gałosz, 2004;Zalewska-Gałosz, Ronikier & Kaplan, 2009Kaplan, Fehrer & Hellquist, 2011;Kaplan & Uotila, 2011). Only a few studies have recently dealt with the morphological delimitation of species (e.g.…”